THE WAIKATO RIVER.

Waikato Times, Volume 94, Issue 14770, 8 October 1921, Page 9 (Supplement)

THE WAIKATO RIVER.

ITS POTENTIALITIES. (By A.M.N.Z. Inst. C.E, Navigation. — (Continued). Carriage by water must always be cheaper than by rail within cerium limits of distance, and if time docs not matter. This was so under the old system of towage. How much more is it now with ’internal combustion engines driving the canal boats, and how much still more so will it be when the water from its own river generates Hs own electric driving force? Distance will be eliminated as time is shortened, and the canal will once more be able to take its place beside the railway, and compete with it for freight. This will depend, of course, upon the water scheme being initialed and managed economically. No scheme can me run economically that has been over capitalised, or which is too much in advance of its time. Therefore, very' much will depend upon Hie way this project is designed and managed, especially at the’start. This point will be elaborated in a future article. But, given a fair start, the navigation of the Waikato should be a huge success from tile beginning, and it should increase in value and usefulness year b> year.

Competition with Railways. And now with regard lo the question of competition with the railways. This frightens timid persons, and such politicians and officials as are incapable of foresight. Of course there must be competition—and a very good tiling, too; but it will be fair competition—not the absorption of the railway in the canal. Canals are going to return to the railways good for the evil done in time past. It is simply nonsense lo •imagine that the Main Truna railway will be ruined by Hie river. With cheap power and cheap carriage the population of the Waikato Valley will before long approximate that of all New Zealand to-day. Then it will be necessary' to duplicate, and 'in parts quadruplicate, the Main Trunk line, and to construct new feeders to it m order In carry - Hie traffic brought to the increased population by the river. Then the river will be the friend and the partner, not the foe and the rival of the railway. Each will bring traffic to the other.

And long before that time arrives the river will be able to cater for merchandise which it. is impossible to send now profitably by rail. Firewood is a case in point—-and a very sore point it Is with unfortunate, tormented Auckland housewives. A settler near the river, in clearing his land for cultivation, need not burn off his timber, but may cut it up for the market by means of a small oil engine, and send it cheaply to market, where it will find a. ready sale. And so with heavy and imperishable goods, when time is no object. Those can certainly be earned much more cheaply by water than by rail, when once the river is made fit for traffic.

Gf course flris implies direct water communication between (at least) Auckland and Cambridge. Its practicability must be left to a later article. Hut we should at nnee get a vision of a great seheme which will link the Waikato with the Manukau. and this .with the Waitamaia. and this again with the Kaipara. Then the products of one locality V-111 be taken, with hut one loading and one unloading, between any two points on this vast waterfront, at a fraction of the present cost of handling them. How much would this reduce the nriee of commodities and make this province a happy land? V. THE MIDDLE AND LOWER SECTIONS AND THE HARBOUR. The middle section of the river, viz., that from Cambridge to Rangiriri, is the only part that can he said to be navigable. There is sufficient fall in Ihc river-bed to give a current of about eight miles an hour, and the bed is narrow enough to make this current scour the channel. Consequently navigation is easy. It will, of course, be necessary lo guard against erosion and pollution, and minor improvemenls may he effected: but the controlling authority to be, created will be able, after the detailed survey has been made, to do what is required, as it is needed, at litlle cost. The lower section and the harbour are works which will require much skill and expenditure, and to these we must devote sonic thought. As water slackens it, deposits the solids it holds in suspension. The stream also spreads, and thus it loses its capacity to scour. The gradient of the river-bed below Rangiriri is a very flat one, and, consequently, the stream is slow', wide and shallow. Where islands occur, and Ihc water is confined between narrower limits, some scour takes place when the river is in (tool. From this short, and necessarily very incomplete, descriplinn Ihe average layman will understand that by confining the channel between training walls of rubble, a navigable channel —at least for vessels of light, draught—can be secured. These will lie so constructed ns to allow' flood waters lo cover the whole of the river-bed, while at the same time, their main force being dicretcd between the walls, it, will, from time to time, clean out the channel. Judicious dredging will do what ever else is needed to keep a fair-way open for navigation. Such training walls have been successfully used in Australian coastal rivers, which have only the tidal scour, and practically no fresh water current, to rely on.

It is here that navigation and drainage come into conflict. It has been, wc understand, the practice In drain the adjoining swamps into ttic river without regard to the quantity of sill discharged into the channel. Drainage 5s of local benefit. Navigation is the right, and to the advantage of. the whole riparian area. It is obvious Hint drainage must give place to navigation. and the controlling authority must he clothed with power to abate this nuisance summarily. How this may be done, and how holh interests may be harmonised, will he dealt with in the article on Pollution and Drainngc. Rut wc most take note here of Hie axiom that Navigation must take precedence over everything except Power. (To be continued.)